﻿/*******************************************************************************************
 * Copyright (c) 2006-2009 Alex Robson, Rob Simmons, Craig Israel, and Rachel Twyford
 *
 * Use of this software in any form requires that you have both 
 * read and agreed to the following terms:
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the "Software"), 
 * to deal in the Software without restriction, including without limitation 
 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions: 
 *
 * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * Redistributions in binary form must reproduce the above copyright notice, 
 * this list of conditions and the following disclaimer in the 
 * documentation and/or other materials provided with the distribution.
 * Neither the name of Nvigorate nor the names of its contributors may 
 * be used to endorse or promote products derived from this software without 
 * specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
 * DISCLAIMED. IN NO EVENT SHALL ANY CONTRIBUTOR BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * ****************************************************************************************/

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Nvigorate.Common;
using Nvigorate.Common.Reflection;

namespace Nvigorate.Extensions
{
    public static class IEnumerableExtenders
    {
        /// <summary>
        /// Flattens jagged array into a single dimensioned, uniform IEnumerable
        /// </summary>
        /// <param name="jaggedCollection">The heterogeneous collection</param>
        /// <returns>Uniform IEnumerable</returns>
        public static IEnumerable<object> Denormalize(this IEnumerable<object> jaggedCollection)
        {
            return new List<object>()
                .Concat(
                    jaggedCollection
                        .Where(e => e != null && e.GetType() != typeof(string))
                        .OfType<IEnumerable>()
                        .SelectMany(e => e.OfType<object>()))
                .Concat(
                    jaggedCollection
                        .Where(o => o as IEnumerable == null || o.GetType() == typeof(string))
                );
        }

        public static IEnumerable<T> Flatten<T>(this IEnumerable<IEnumerable<T>> nestedCollection)
        {
            return nestedCollection.SelectMany(c => c);
        }

        /// <summary>
        /// Creates a Dictionary by associating the keys and values based on their order
        /// </summary>
        /// <typeparam name="K"></typeparam>
        /// <typeparam name="V"></typeparam>
        /// <param name="keys">The collection to create keys from</param>
        /// <param name="values">The collection to create values from</param>
        /// <returns>A dictionary containing N elements where N is the smallest count between keys and values</returns>
        public static Dictionary<K, V> ZipToDictionary<K, V>(this IEnumerable<K> keys, IEnumerable<V> values)
        {
            var keyList = new List<K>();
            return keys.Take(values.Count()).ToDictionary(
                key =>
                {
                    keyList.Add(key);
                    return key;
                },
                key => values.ElementAt(keyList.Count - 1));
        }

        /// <summary>
        /// Creates a Dictionary by associating the keys and values based on their order
        /// </summary>
        /// <typeparam name="K"></typeparam>
        /// <typeparam name="V"></typeparam>
        /// <param name="keys">The collection to create keys from</param>
        /// <param name="values">The collection to create values from</param>
        /// <returns>A list of Tuples containing N elements where N is the smallest count between keys and values</returns>
        public static List<Tuple<K, V>> Zip<K, V>(this IEnumerable<K> collection1, IEnumerable<V> collection2)
        {
            var index = 0;
            return collection1
                    .Take(collection2.Count())
                    .Select<K, Tuple<K,V>>(value1 => Tuple.Create(value1, collection2.ElementAt(index++)))
                    .ToList();
        }

        public static void ForEach<T>(this IEnumerable<T> enumerable, Action<T> action)
        {
            if (enumerable == null)
                return;

            if(action == null)
                throw new ArgumentNullException("action");
            
            foreach (var t in enumerable)
            {
                action(t);
            }
        }

        public static IEnumerable<T> Select<T>(this IEnumerable enumerable, Func<object, T> selector)
        {
            foreach (var t in enumerable)
            {
                yield return selector(t);
            }
        }

        public static string BuildString(this IEnumerable<string> source, string delimited)
        {
            return DelimitedBuilder.Construct(source, delimited);
        }

        public static bool SequenceEquals(this IEnumerable enumerable1, IEnumerable enumerable2)
        {
            try
            {
                IEnumerator enumerator1 = enumerable1.GetEnumerator();
                IEnumerator enumerator2 = enumerable2.GetEnumerator();
                while (enumerator1.MoveNext())
                {
                    if (!enumerator2.MoveNext() || !Reflector.AreEqualValue(enumerator1.Current, enumerator2.Current))
                    {
                        return false;
                    }
                }
                if (enumerator2.MoveNext())
                {
                    return false;
                }
            
                return true;
            }
            catch (Exception e)
            {
                return false;
            }

        }
    }
}
